xref: /openbmc/linux/drivers/ssb/pcmcia.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * Sonics Silicon Backplane
3  * PCMCIA-Hostbus related functions
4  *
5  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
6  * Copyright 2007 Michael Buesch <mb@bu3sch.de>
7  *
8  * Licensed under the GNU/GPL. See COPYING for details.
9  */
10 
11 #include <linux/ssb/ssb.h>
12 #include <linux/delay.h>
13 #include <linux/io.h>
14 
15 #include <pcmcia/cs_types.h>
16 #include <pcmcia/cs.h>
17 #include <pcmcia/cistpl.h>
18 #include <pcmcia/ciscode.h>
19 #include <pcmcia/ds.h>
20 #include <pcmcia/cisreg.h>
21 
22 #include "ssb_private.h"
23 
24 
25 /* Define the following to 1 to enable a printk on each coreswitch. */
26 #define SSB_VERBOSE_PCMCIACORESWITCH_DEBUG		0
27 
28 
29 int ssb_pcmcia_switch_coreidx(struct ssb_bus *bus,
30 			      u8 coreidx)
31 {
32 	struct pcmcia_device *pdev = bus->host_pcmcia;
33 	int err;
34 	int attempts = 0;
35 	u32 cur_core;
36 	conf_reg_t reg;
37 	u32 addr;
38 	u32 read_addr;
39 
40 	addr = (coreidx * SSB_CORE_SIZE) + SSB_ENUM_BASE;
41 	while (1) {
42 		reg.Action = CS_WRITE;
43 		reg.Offset = 0x2E;
44 		reg.Value = (addr & 0x0000F000) >> 12;
45 		err = pcmcia_access_configuration_register(pdev, &reg);
46 		if (err != CS_SUCCESS)
47 			goto error;
48 		reg.Offset = 0x30;
49 		reg.Value = (addr & 0x00FF0000) >> 16;
50 		err = pcmcia_access_configuration_register(pdev, &reg);
51 		if (err != CS_SUCCESS)
52 			goto error;
53 		reg.Offset = 0x32;
54 		reg.Value = (addr & 0xFF000000) >> 24;
55 		err = pcmcia_access_configuration_register(pdev, &reg);
56 		if (err != CS_SUCCESS)
57 			goto error;
58 
59 		read_addr = 0;
60 
61 		reg.Action = CS_READ;
62 		reg.Offset = 0x2E;
63 		err = pcmcia_access_configuration_register(pdev, &reg);
64 		if (err != CS_SUCCESS)
65 			goto error;
66 		read_addr |= (reg.Value & 0xF) << 12;
67 		reg.Offset = 0x30;
68 		err = pcmcia_access_configuration_register(pdev, &reg);
69 		if (err != CS_SUCCESS)
70 			goto error;
71 		read_addr |= reg.Value << 16;
72 		reg.Offset = 0x32;
73 		err = pcmcia_access_configuration_register(pdev, &reg);
74 		if (err != CS_SUCCESS)
75 			goto error;
76 		read_addr |= reg.Value << 24;
77 
78 		cur_core = (read_addr - SSB_ENUM_BASE) / SSB_CORE_SIZE;
79 		if (cur_core == coreidx)
80 			break;
81 
82 		if (attempts++ > SSB_BAR0_MAX_RETRIES)
83 			goto error;
84 		udelay(10);
85 	}
86 
87 	return 0;
88 error:
89 	ssb_printk(KERN_ERR PFX "Failed to switch to core %u\n", coreidx);
90 	return -ENODEV;
91 }
92 
93 int ssb_pcmcia_switch_core(struct ssb_bus *bus,
94 			   struct ssb_device *dev)
95 {
96 	int err;
97 	unsigned long flags;
98 
99 #if SSB_VERBOSE_PCMCIACORESWITCH_DEBUG
100 	ssb_printk(KERN_INFO PFX
101 		   "Switching to %s core, index %d\n",
102 		   ssb_core_name(dev->id.coreid),
103 		   dev->core_index);
104 #endif
105 
106 	spin_lock_irqsave(&bus->bar_lock, flags);
107 	err = ssb_pcmcia_switch_coreidx(bus, dev->core_index);
108 	if (!err)
109 		bus->mapped_device = dev;
110 	spin_unlock_irqrestore(&bus->bar_lock, flags);
111 
112 	return err;
113 }
114 
115 int ssb_pcmcia_switch_segment(struct ssb_bus *bus, u8 seg)
116 {
117 	int attempts = 0;
118 	unsigned long flags;
119 	conf_reg_t reg;
120 	int res, err = 0;
121 
122 	SSB_WARN_ON((seg != 0) && (seg != 1));
123 	reg.Offset = 0x34;
124 	reg.Function = 0;
125 	spin_lock_irqsave(&bus->bar_lock, flags);
126 	while (1) {
127 		reg.Action = CS_WRITE;
128 		reg.Value = seg;
129 		res = pcmcia_access_configuration_register(bus->host_pcmcia, &reg);
130 		if (unlikely(res != CS_SUCCESS))
131 			goto error;
132 		reg.Value = 0xFF;
133 		reg.Action = CS_READ;
134 		res = pcmcia_access_configuration_register(bus->host_pcmcia, &reg);
135 		if (unlikely(res != CS_SUCCESS))
136 			goto error;
137 
138 		if (reg.Value == seg)
139 			break;
140 
141 		if (unlikely(attempts++ > SSB_BAR0_MAX_RETRIES))
142 			goto error;
143 		udelay(10);
144 	}
145 	bus->mapped_pcmcia_seg = seg;
146 out_unlock:
147 	spin_unlock_irqrestore(&bus->bar_lock, flags);
148 	return err;
149 error:
150 	ssb_printk(KERN_ERR PFX "Failed to switch pcmcia segment\n");
151 	err = -ENODEV;
152 	goto out_unlock;
153 }
154 
155 /* These are the main device register access functions.
156  * do_select_core is inline to have the likely hotpath inline.
157  * All unlikely codepaths are out-of-line. */
158 static inline int do_select_core(struct ssb_bus *bus,
159 				 struct ssb_device *dev,
160 				 u16 *offset)
161 {
162 	int err;
163 	u8 need_seg = (*offset >= 0x800) ? 1 : 0;
164 
165 	if (unlikely(dev != bus->mapped_device)) {
166 		err = ssb_pcmcia_switch_core(bus, dev);
167 		if (unlikely(err))
168 			return err;
169 	}
170 	if (unlikely(need_seg != bus->mapped_pcmcia_seg)) {
171 		err = ssb_pcmcia_switch_segment(bus, need_seg);
172 		if (unlikely(err))
173 			return err;
174 	}
175 	if (need_seg == 1)
176 		*offset -= 0x800;
177 
178 	return 0;
179 }
180 
181 static u16 ssb_pcmcia_read16(struct ssb_device *dev, u16 offset)
182 {
183 	struct ssb_bus *bus = dev->bus;
184 	u16 x;
185 
186 	if (unlikely(do_select_core(bus, dev, &offset)))
187 		return 0xFFFF;
188 	x = readw(bus->mmio + offset);
189 
190 	return x;
191 }
192 
193 static u32 ssb_pcmcia_read32(struct ssb_device *dev, u16 offset)
194 {
195 	struct ssb_bus *bus = dev->bus;
196 	u32 x;
197 
198 	if (unlikely(do_select_core(bus, dev, &offset)))
199 		return 0xFFFFFFFF;
200 	x = readl(bus->mmio + offset);
201 
202 	return x;
203 }
204 
205 static void ssb_pcmcia_write16(struct ssb_device *dev, u16 offset, u16 value)
206 {
207 	struct ssb_bus *bus = dev->bus;
208 
209 	if (unlikely(do_select_core(bus, dev, &offset)))
210 		return;
211 	writew(value, bus->mmio + offset);
212 }
213 
214 static void ssb_pcmcia_write32(struct ssb_device *dev, u16 offset, u32 value)
215 {
216 	struct ssb_bus *bus = dev->bus;
217 
218 	if (unlikely(do_select_core(bus, dev, &offset)))
219 		return;
220 	readw(bus->mmio + offset);
221 	writew(value >> 16, bus->mmio + offset + 2);
222 	readw(bus->mmio + offset);
223 	writew(value, bus->mmio + offset);
224 }
225 
226 /* Not "static", as it's used in main.c */
227 const struct ssb_bus_ops ssb_pcmcia_ops = {
228 	.read16		= ssb_pcmcia_read16,
229 	.read32		= ssb_pcmcia_read32,
230 	.write16	= ssb_pcmcia_write16,
231 	.write32	= ssb_pcmcia_write32,
232 };
233 
234 int ssb_pcmcia_get_invariants(struct ssb_bus *bus,
235 			      struct ssb_init_invariants *iv)
236 {
237 	//TODO
238 	return 0;
239 }
240 
241 int ssb_pcmcia_init(struct ssb_bus *bus)
242 {
243 	conf_reg_t reg;
244 	int err;
245 
246 	if (bus->bustype != SSB_BUSTYPE_PCMCIA)
247 		return 0;
248 
249 	/* Switch segment to a known state and sync
250 	 * bus->mapped_pcmcia_seg with hardware state. */
251 	ssb_pcmcia_switch_segment(bus, 0);
252 
253 	/* Init IRQ routing */
254 	reg.Action = CS_READ;
255 	reg.Function = 0;
256 	if (bus->chip_id == 0x4306)
257 		reg.Offset = 0x00;
258 	else
259 		reg.Offset = 0x80;
260 	err = pcmcia_access_configuration_register(bus->host_pcmcia, &reg);
261 	if (err != CS_SUCCESS)
262 		goto error;
263 	reg.Action = CS_WRITE;
264 	reg.Value |= 0x04 | 0x01;
265 	err = pcmcia_access_configuration_register(bus->host_pcmcia, &reg);
266 	if (err != CS_SUCCESS)
267 		goto error;
268 
269 	return 0;
270 error:
271 	return -ENODEV;
272 }
273